1. Field of the Invention
This invention relates generally to a water snorkel for swimming that has enhanced hydrodynamic and ergonomic properties. More specifically, the invention relates to a breathing tube having a flexible lower portion and a cross-sectional profile that allows it to conform to the face of the user and offer a minimum of resistance to the water.
2. Description of the Related Art
The use of a breathing tube to allow a swimmer to maintain facial position below the surface of the water is well known. Snorkels are useful in clear water to allow observation of underwater plant and animal life. Snorkels can also be used to allow movement with greater speed and efficiency through the water.
A swimmer will stroke with ideal efficiency when his or her face is in the water, but the back of the head remains out of the water. Many swimmers find breathing difficult while maintaining ideal stroke form, as pushing the chin forward to lift the back of the head out of the water creates a strain in the trachea.
Moreover, when a swimmer raises his or her head to breathe, the hips and legs sink into the water. A two-inch vertical lift of the head can result in a four- to six-inch drop of the hips, and a corresponding eight- to twelve-inch drop of the feet. This departure from ideal stroke form can double the frontal surface area offered to the water, thereby doubling the water resistance encountered by the swimmer.
Because a snorkel allows the swimmer to breathe without raising his or her head, snorkels have been used to assist athletes train for competition. One example of a snorkel designed for swimmers is the "Finis Center Mount Swimmer's Snorkel" (hereafter "the Finis snorkel") manufactured by Finis, Inc. of Tracy, Calif.
FIG. 1 illustrates a profile view of the Finis snorkel. The Finis snorkel 100 includes a breathing tube 102 that extends out from the mouth and includes an upper portion 104 which extends upward at the center of the face between the eyes of the user, with open end 106 ultimately projecting above the surface of the water. Breathing tube 102 also includes a downward portion 108 housing a water reservoir 110 and a purge valve 112.
While the Finis snorkel is useful for training, it suffers from a number of disadvantages.
First, purge valve 112 is a traditional design used for diving. In order to activate conventional diving purge valve 112, reservoir 110 must be filled with water above the mouth area. When the user sharply exhales, water in the snorkel is forced upward, and provides sufficient back pressure to offset external water pressure and activate the purge valve. Accumulated air and water are expunged, and the swimmer can breathe again.
When a snorkel is used by a scuba diver, water normally fills the entire snorkel and the conventional purge valve works adequately. However, when a snorkel is used primarily for surface activities such as swimming and snorkeling, the snorkel will contain some water but will not ordinarily become filled.
The conventional diving-type purge valve of the Finis snorkel is thus unsuited for swimming and snorkeling, as a relatively large volume of water must accumulate in the snorkel before it can be purged. This accumulated water consumes valuable air space, decreasing the flow of air available to the swimmer. Accumulated water can also splash into the swimmer's airway, making breathing uncomfortable.
A second disadvantage of the Finis snorkel is that the cross-section of breathing tube 102 is designed to be as narrow as possible. The narrowness of breathing tube 102 is intended to offer minimum resistance while the user's face is underwater, and also to force the user to breathe harder and thereby enhance aerobic activity during training.
However, in applications such as open water swimming or snorkeling, safety rather than fitness is of paramount concern and a narrow breathing tube could interfere with necessary and proper breathing. Moreover, use of a narrow breathing tube does not necessarily ensure that water resistance will be kept to a minimum.
A third disadvantage of the Finis snorkel is the manner in which it is worn. The Finis snorkel is held to the forehead by thick plastic headband 114. Headband 114 must be worn tight around the head, and is made of solid plastic to ensure secure attachment. Headband 114 may exert an uncomfortable pressure upon the swimmer's brow.
Moreover, in order to don the snorkel, the user must turn mouthpiece 116 to one side and then slide headband 114 down over the forehead, finally turning mouthpiece 116 back to fit within the mouth. Furthermore, headband 114 does not have a release clip, making it difficult to remove the snorkel.
A fourth disadvantage of the Finis snorkel is that open end 106 of breathing tube 102 projects substantially vertically above the water surface. This shape permits water to enter the snorkel via splashing from the swimmer or those nearby.
A fifth disadvantage of the Finis snorkel is that upper portion 104 of breathing tube 102 is located in front of the face and between the eyes of the user. This positioning interferes with the swimmer's line of vision of the swimmer, conveying the unpleasant sensation of being cross-eyed.
A sixth disadvantage of the Finis snorkel is that breathing tube 102 is fixed by headband 114 at a distance from the face of the user. Gap 118 between the swimmer's head and the breathing tube contributes turbulence and drag to movement of the snorkel through the water, and also permits the snorkel to move from side-to-side in response to resistance offered by the water. This "wavering" of the snorkel is distracting to the user, and also creates additional water resistance to impede movement of the swimmer through the water.
Given the above-listed disadvantages, there is a need in the art for a snorkel design that permits a swimmer to efficiently move through the water with a minimum of drag and a maximum of comfort.